ios_base.h revision 132720
1// Iostreams base classes -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31//
32// ISO C++ 14882: 27.4  Iostreams base classes
33//
34
35/** @file ios_base.h
36 *  This is an internal header file, included by other library headers.
37 *  You should not attempt to use it directly.
38 */
39
40#ifndef _IOS_BASE_H
41#define _IOS_BASE_H 1
42
43#pragma GCC system_header
44
45#include <bits/atomicity.h>
46#include <bits/localefwd.h>
47#include <bits/locale_classes.h>
48
49namespace std
50{
51  // The following definitions of bitmask types are enums, not ints,
52  // as permitted (but not required) in the standard, in order to provide
53  // better type safety in iostream calls.  A side effect is that
54  // expressions involving them are no longer compile-time constants.
55  enum _Ios_Fmtflags { _S_ios_fmtflags_end = 1L << 16 };
56
57  inline _Ios_Fmtflags
58  operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
59  { return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
60
61  inline _Ios_Fmtflags
62  operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
63  { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
64
65  inline _Ios_Fmtflags
66  operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
67  { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
68
69  inline _Ios_Fmtflags
70  operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
71  { return __a = __a | __b; }
72
73  inline _Ios_Fmtflags
74  operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
75  { return __a = __a & __b; }
76
77  inline _Ios_Fmtflags
78  operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
79  { return __a = __a ^ __b; }
80
81  inline _Ios_Fmtflags
82  operator~(_Ios_Fmtflags __a)
83  { return _Ios_Fmtflags(~static_cast<int>(__a)); }
84
85
86  enum _Ios_Openmode { _S_ios_openmode_end = 1L << 16 };
87
88  inline _Ios_Openmode
89  operator&(_Ios_Openmode __a, _Ios_Openmode __b)
90  { return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
91
92  inline _Ios_Openmode
93  operator|(_Ios_Openmode __a, _Ios_Openmode __b)
94  { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
95
96  inline _Ios_Openmode
97  operator^(_Ios_Openmode __a, _Ios_Openmode __b)
98  { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
99
100  inline _Ios_Openmode
101  operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
102  { return __a = __a | __b; }
103
104  inline _Ios_Openmode
105  operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
106  { return __a = __a & __b; }
107
108  inline _Ios_Openmode
109  operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
110  { return __a = __a ^ __b; }
111
112  inline _Ios_Openmode
113  operator~(_Ios_Openmode __a)
114  { return _Ios_Openmode(~static_cast<int>(__a)); }
115
116
117  enum _Ios_Iostate { _S_ios_iostate_end = 1L << 16 };
118
119  inline _Ios_Iostate
120  operator&(_Ios_Iostate __a, _Ios_Iostate __b)
121  { return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
122
123  inline _Ios_Iostate
124  operator|(_Ios_Iostate __a, _Ios_Iostate __b)
125  { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
126
127  inline _Ios_Iostate
128  operator^(_Ios_Iostate __a, _Ios_Iostate __b)
129  { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
130
131  inline _Ios_Iostate
132  operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
133  { return __a = __a | __b; }
134
135  inline _Ios_Iostate
136  operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
137  { return __a = __a & __b; }
138
139  inline _Ios_Iostate
140  operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
141  { return __a = __a ^ __b; }
142
143  inline _Ios_Iostate
144  operator~(_Ios_Iostate __a)
145  { return _Ios_Iostate(~static_cast<int>(__a)); }
146
147  enum _Ios_Seekdir { _S_ios_seekdir_end = 1L << 16 };
148
149  // 27.4.2  Class ios_base
150  /**
151   *  @brief  The very top of the I/O class hierarchy.
152   *
153   *  This class defines everything that can be defined about I/O that does
154   *  not depend on the type of characters being input or output.  Most
155   *  people will only see @c ios_base when they need to specify the full
156   *  name of the various I/O flags (e.g., the openmodes).
157  */
158  class ios_base
159  {
160  public:
161
162    // 27.4.2.1.1  Class ios_base::failure
163    /// These are thrown to indicate problems.  Doc me.
164    class failure : public exception
165    {
166    public:
167      // _GLIBCXX_RESOLVE_LIB_DEFECTS
168      // 48.  Use of non-existent exception constructor
169      explicit
170      failure(const string& __str) throw();
171
172      // This declaration is not useless:
173      // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
174      virtual
175      ~failure() throw();
176
177      virtual const char*
178      what() const throw();
179
180    private:
181      string _M_msg;
182    };
183
184    // 27.4.2.1.2  Type ios_base::fmtflags
185    /**
186     *  @brief This is a bitmask type.
187     *
188     *  @c "_Ios_Fmtflags" is implementation-defined, but it is valid to
189     *  perform bitwise operations on these values and expect the Right
190     *  Thing to happen.  Defined objects of type fmtflags are:
191     *  - boolalpha
192     *  - dec
193     *  - fixed
194     *  - hex
195     *  - internal
196     *  - left
197     *  - oct
198     *  - right
199     *  - scientific
200     *  - showbase
201     *  - showpoint
202     *  - showpos
203     *  - skipws
204     *  - unitbuf
205     *  - uppercase
206     *  - adjustfield
207     *  - basefield
208     *  - floatfield
209    */
210    typedef _Ios_Fmtflags fmtflags;
211
212    /// Insert/extract @c bool in alphabetic rather than numeric format.
213    static const fmtflags boolalpha =   fmtflags(__ios_flags::_S_boolalpha);
214
215    /// Converts integer input or generates integer output in decimal base.
216    static const fmtflags dec =         fmtflags(__ios_flags::_S_dec);
217
218    /// Generate floating-point output in fixed-point notation.
219    static const fmtflags fixed =       fmtflags(__ios_flags::_S_fixed);
220
221    /// Converts integer input or generates integer output in hexadecimal base.
222    static const fmtflags hex =         fmtflags(__ios_flags::_S_hex);
223
224    /// Adds fill characters at a designated internal point in certain
225    /// generated output, or identical to @c right if no such point is
226    /// designated.
227    static const fmtflags internal =    fmtflags(__ios_flags::_S_internal);
228
229    /// Adds fill characters on the right (final positions) of certain
230    /// generated output.  (I.e., the thing you print is flush left.)
231    static const fmtflags left =        fmtflags(__ios_flags::_S_left);
232
233    /// Converts integer input or generates integer output in octal base.
234    static const fmtflags oct =         fmtflags(__ios_flags::_S_oct);
235
236    /// Adds fill characters on the left (initial positions) of certain
237    /// generated output.  (I.e., the thing you print is flush right.)
238    static const fmtflags right =       fmtflags(__ios_flags::_S_right);
239
240    /// Generates floating-point output in scientific notation.
241    static const fmtflags scientific =  fmtflags(__ios_flags::_S_scientific);
242
243    /// Generates a prefix indicating the numeric base of generated integer
244    /// output.
245    static const fmtflags showbase =    fmtflags(__ios_flags::_S_showbase);
246
247    /// Generates a decimal-point character unconditionally in generated
248    /// floating-point output.
249    static const fmtflags showpoint =   fmtflags(__ios_flags::_S_showpoint);
250
251    /// Generates a + sign in non-negative generated numeric output.
252    static const fmtflags showpos =     fmtflags(__ios_flags::_S_showpos);
253
254    /// Skips leading white space before certain input operations.
255    static const fmtflags skipws =      fmtflags(__ios_flags::_S_skipws);
256
257    /// Flushes output after each output operation.
258    static const fmtflags unitbuf =     fmtflags(__ios_flags::_S_unitbuf);
259
260    /// Replaces certain lowercase letters with their uppercase equivalents
261    /// in generated output.
262    static const fmtflags uppercase =   fmtflags(__ios_flags::_S_uppercase);
263
264    /// A mask of left|right|internal.  Useful for the 2-arg form of @c setf.
265    static const fmtflags adjustfield = fmtflags(__ios_flags::_S_adjustfield);
266
267    /// A mask of dec|oct|hex.  Useful for the 2-arg form of @c setf.
268    static const fmtflags basefield =   fmtflags(__ios_flags::_S_basefield);
269
270    /// A mask of scientific|fixed.  Useful for the 2-arg form of @c setf.
271    static const fmtflags floatfield =  fmtflags(__ios_flags::_S_floatfield);
272
273    // 27.4.2.1.3  Type ios_base::iostate
274    /**
275     *  @brief This is a bitmask type.
276     *
277     *  @c "_Ios_Iostate" is implementation-defined, but it is valid to
278     *  perform bitwise operations on these values and expect the Right
279     *  Thing to happen.  Defined objects of type iostate are:
280     *  - badbit
281     *  - eofbit
282     *  - failbit
283     *  - goodbit
284    */
285    typedef _Ios_Iostate iostate;
286
287    /// Indicates a loss of integrity in an input or output sequence (such
288    /// as an irrecoverable read error from a file).
289    static const iostate badbit =	iostate(__ios_flags::_S_badbit);
290
291    /// Indicates that an input operation reached the end of an input sequence.
292    static const iostate eofbit =	iostate(__ios_flags::_S_eofbit);
293
294    /// Indicates that an input operation failed to read the expected
295    /// characters, or that an output operation failed to generate the
296    /// desired characters.
297    static const iostate failbit =	iostate(__ios_flags::_S_failbit);
298
299    /// Indicates all is well.
300    static const iostate goodbit =	iostate(0);
301
302    // 27.4.2.1.4  Type ios_base::openmode
303    /**
304     *  @brief This is a bitmask type.
305     *
306     *  @c "_Ios_Openmode" is implementation-defined, but it is valid to
307     *  perform bitwise operations on these values and expect the Right
308     *  Thing to happen.  Defined objects of type openmode are:
309     *  - app
310     *  - ate
311     *  - binary
312     *  - in
313     *  - out
314     *  - trunc
315    */
316    typedef _Ios_Openmode openmode;
317
318    /// Seek to end before each write.
319    static const openmode app =		openmode(__ios_flags::_S_app);
320
321    /// Open and seek to end immediately after opening.
322    static const openmode ate =		openmode(__ios_flags::_S_ate);
323
324    /// Perform input and output in binary mode (as opposed to text mode).
325    /// This is probably not what you think it is; see
326    /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#3 and
327    /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#7 for more.
328    static const openmode binary =	openmode(__ios_flags::_S_bin);
329
330    /// Open for input.  Default for @c ifstream and fstream.
331    static const openmode in =		openmode(__ios_flags::_S_in);
332
333    /// Open for output.  Default for @c ofstream and fstream.
334    static const openmode out =		openmode(__ios_flags::_S_out);
335
336    /// Open for input.  Default for @c ofstream.
337    static const openmode trunc =	openmode(__ios_flags::_S_trunc);
338
339    // 27.4.2.1.5  Type ios_base::seekdir
340    /**
341     *  @brief This is an enumerated type.
342     *
343     *  @c "_Ios_Seekdir" is implementation-defined.  Defined values
344     *  of type seekdir are:
345     *  - beg
346     *  - cur, equivalent to @c SEEK_CUR in the C standard library.
347     *  - end, equivalent to @c SEEK_END in the C standard library.
348    */
349    typedef _Ios_Seekdir seekdir;
350
351    /// Request a seek relative to the beginning of the stream.
352    static const seekdir beg =		seekdir(0);
353
354    /// Request a seek relative to the current position within the sequence.
355    static const seekdir cur =		seekdir(SEEK_CUR);
356
357    /// Request a seek relative to the current end of the sequence.
358    static const seekdir end =		seekdir(SEEK_END);
359
360#ifdef _GLIBCXX_DEPRECATED
361    // Annex D.6
362    typedef int io_state;
363    typedef int open_mode;
364    typedef int seek_dir;
365
366    typedef std::streampos streampos;
367    typedef std::streamoff streamoff;
368#endif
369
370    // Callbacks;
371    /**
372     *  @brief  The set of events that may be passed to an event callback.
373     *
374     *  erase_event is used during ~ios() and copyfmt().  imbue_event is used
375     *  during imbue().  copyfmt_event is used during copyfmt().
376    */
377    enum event
378    {
379      erase_event,
380      imbue_event,
381      copyfmt_event
382    };
383
384    /**
385     *  @brief  The type of an event callback function.
386     *  @param  event  One of the members of the event enum.
387     *  @param  ios_base  Reference to the ios_base object.
388     *  @param  int  The integer provided when the callback was registered.
389     *
390     *  Event callbacks are user defined functions that get called during
391     *  several ios_base and basic_ios functions, specifically imbue(),
392     *  copyfmt(), and ~ios().
393    */
394    typedef void (*event_callback) (event, ios_base&, int);
395
396    /**
397     *  @brief  Add the callback __fn with parameter __index.
398     *  @param  __fn  The function to add.
399     *  @param  __index  The integer to pass to the function when invoked.
400     *
401     *  Registers a function as an event callback with an integer parameter to
402     *  be passed to the function when invoked.  Multiple copies of the
403     *  function are allowed.  If there are multiple callbacks, they are
404     *  invoked in the order they were registered.
405    */
406    void
407    register_callback(event_callback __fn, int __index);
408
409  protected:
410    //@{
411    /**
412     *  @if maint
413     *  ios_base data members (doc me)
414     *  @endif
415    */
416    streamsize		_M_precision;
417    streamsize		_M_width;
418    fmtflags		_M_flags;
419    iostate		_M_exception;
420    iostate		_M_streambuf_state;
421    //@}
422
423    // 27.4.2.6  Members for callbacks
424    // 27.4.2.6  ios_base callbacks
425    struct _Callback_list
426    {
427      // Data Members
428      _Callback_list*		_M_next;
429      ios_base::event_callback	_M_fn;
430      int			_M_index;
431      _Atomic_word		_M_refcount;  // 0 means one reference.
432
433      _Callback_list(ios_base::event_callback __fn, int __index,
434		     _Callback_list* __cb)
435      : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
436
437      void
438      _M_add_reference() { __gnu_cxx::__atomic_add(&_M_refcount, 1); }
439
440      // 0 => OK to delete.
441      int
442      _M_remove_reference()
443      { return __gnu_cxx::__exchange_and_add(&_M_refcount, -1); }
444    };
445
446     _Callback_list*	_M_callbacks;
447
448    void
449    _M_call_callbacks(event __ev) throw();
450
451    void
452    _M_dispose_callbacks(void);
453
454    // 27.4.2.5  Members for iword/pword storage
455    struct _Words
456    {
457      void*	_M_pword;
458      long	_M_iword;
459      _Words() : _M_pword(0), _M_iword(0) { }
460    };
461
462    // Only for failed iword/pword calls.
463    _Words		_M_word_zero;
464
465    // Guaranteed storage.
466    // The first 5 iword and pword slots are reserved for internal use.
467    static const int	_S_local_word_size = 8;
468    _Words		_M_local_word[_S_local_word_size];
469
470    // Allocated storage.
471    int			_M_word_size;
472    _Words*		_M_word;
473
474    _Words&
475    _M_grow_words(int __index, bool __iword);
476
477    // Members for locale and locale caching.
478    locale		_M_ios_locale;
479
480    void
481    _M_init();
482
483  public:
484
485    // 27.4.2.1.6  Class ios_base::Init
486    // Used to initialize standard streams. In theory, g++ could use
487    // -finit-priority to order this stuff correctly without going
488    // through these machinations.
489    class Init
490    {
491      friend class ios_base;
492    public:
493      Init();
494      ~Init();
495
496    private:
497      static _Atomic_word	_S_refcount;
498      static bool		_S_synced_with_stdio;
499    };
500
501    // [27.4.2.2] fmtflags state functions
502    /**
503     *  @brief  Access to format flags.
504     *  @return  The format control flags for both input and output.
505    */
506    inline fmtflags
507    flags() const { return _M_flags; }
508
509    /**
510     *  @brief  Setting new format flags all at once.
511     *  @param  fmtfl  The new flags to set.
512     *  @return  The previous format control flags.
513     *
514     *  This function overwrites all the format flags with @a fmtfl.
515    */
516    inline fmtflags
517    flags(fmtflags __fmtfl)
518    {
519      fmtflags __old = _M_flags;
520      _M_flags = __fmtfl;
521      return __old;
522    }
523
524    /**
525     *  @brief  Setting new format flags.
526     *  @param  fmtfl  Additional flags to set.
527     *  @return  The previous format control flags.
528     *
529     *  This function sets additional flags in format control.  Flags that
530     *  were previously set remain set.
531    */
532    inline fmtflags
533    setf(fmtflags __fmtfl)
534    {
535      fmtflags __old = _M_flags;
536      _M_flags |= __fmtfl;
537      return __old;
538    }
539
540    /**
541     *  @brief  Setting new format flags.
542     *  @param  fmtfl  Additional flags to set.
543     *  @param  mask  The flags mask for @a fmtfl.
544     *  @return  The previous format control flags.
545     *
546     *  This function clears @a mask in the format flags, then sets
547     *  @a fmtfl @c & @a mask.  An example mask is @c ios_base::adjustfield.
548    */
549    inline fmtflags
550    setf(fmtflags __fmtfl, fmtflags __mask)
551    {
552      fmtflags __old = _M_flags;
553      _M_flags &= ~__mask;
554      _M_flags |= (__fmtfl & __mask);
555      return __old;
556    }
557
558    /**
559     *  @brief  Clearing format flags.
560     *  @param  mask  The flags to unset.
561     *
562     *  This function clears @a mask in the format flags.
563    */
564    inline void
565    unsetf(fmtflags __mask) { _M_flags &= ~__mask; }
566
567    /**
568     *  @brief  Flags access.
569     *  @return  The precision to generate on certain output operations.
570     *
571     *  @if maint
572     *  Be careful if you try to give a definition of "precision" here; see
573     *  DR 189.
574     *  @endif
575    */
576    inline streamsize
577    precision() const { return _M_precision; }
578
579    /**
580     *  @brief  Changing flags.
581     *  @param  prec  The new precision value.
582     *  @return  The previous value of precision().
583    */
584    inline streamsize
585    precision(streamsize __prec)
586    {
587      streamsize __old = _M_precision;
588      _M_precision = __prec;
589      return __old;
590    }
591
592    /**
593     *  @brief  Flags access.
594     *  @return  The minimum field width to generate on output operations.
595     *
596     *  "Minimum field width" refers to the number of characters.
597    */
598    inline streamsize
599    width() const { return _M_width; }
600
601    /**
602     *  @brief  Changing flags.
603     *  @param  wide  The new width value.
604     *  @return  The previous value of width().
605    */
606    inline streamsize
607    width(streamsize __wide)
608    {
609      streamsize __old = _M_width;
610      _M_width = __wide;
611      return __old;
612    }
613
614    // [27.4.2.4] ios_base static members
615    /**
616     *  @brief  Interaction with the standard C I/O objects.
617     *  @param  sync  Whether to synchronize or not.
618     *  @return  True if the standard streams were previously synchronized.
619     *
620     *  The synchronization referred to is @e only that between the standard
621     *  C facilities (e.g., stdout) and the standard C++ objects (e.g.,
622     *  cout).  User-declared streams are unaffected.  See
623     *  http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#8 for more.
624    */
625    static bool
626    sync_with_stdio(bool __sync = true);
627
628    // [27.4.2.3] ios_base locale functions
629    /**
630     *  @brief  Setting a new locale.
631     *  @param  loc  The new locale.
632     *  @return  The previous locale.
633     *
634     *  Sets the new locale for this stream, and then invokes each callback
635     *  with imbue_event.
636    */
637    locale
638    imbue(const locale& __loc);
639
640    /**
641     *  @brief  Locale access
642     *  @return  A copy of the current locale.
643     *
644     *  If @c imbue(loc) has previously been called, then this function
645     *  returns @c loc.  Otherwise, it returns a copy of @c std::locale(),
646     *  the global C++ locale.
647    */
648    inline locale
649    getloc() const { return _M_ios_locale; }
650
651    /**
652     *  @brief  Locale access
653     *  @return  A reference to the current locale.
654     *
655     *  Like getloc above, but returns a reference instead of
656     *  generating a copy.
657    */
658    inline const locale&
659    _M_getloc() const { return _M_ios_locale; }
660
661    // [27.4.2.5] ios_base storage functions
662    /**
663     *  @brief  Access to unique indices.
664     *  @return  An integer different from all previous calls.
665     *
666     *  This function returns a unique integer every time it is called.  It
667     *  can be used for any purpose, but is primarily intended to be a unique
668     *  index for the iword and pword functions.  The expectation is that an
669     *  application calls xalloc in order to obtain an index in the iword and
670     *  pword arrays that can be used without fear of conflict.
671     *
672     *  The implementation maintains a static variable that is incremented and
673     *  returned on each invocation.  xalloc is guaranteed to return an index
674     *  that is safe to use in the iword and pword arrays.
675    */
676    static int
677    xalloc() throw();
678
679    /**
680     *  @brief  Access to integer array.
681     *  @param  __ix  Index into the array.
682     *  @return  A reference to an integer associated with the index.
683     *
684     *  The iword function provides access to an array of integers that can be
685     *  used for any purpose.  The array grows as required to hold the
686     *  supplied index.  All integers in the array are initialized to 0.
687     *
688     *  The implementation reserves several indices.  You should use xalloc to
689     *  obtain an index that is safe to use.  Also note that since the array
690     *  can grow dynamically, it is not safe to hold onto the reference.
691    */
692    inline long&
693    iword(int __ix)
694    {
695      _Words& __word = (__ix < _M_word_size)
696			? _M_word[__ix] : _M_grow_words(__ix, true);
697      return __word._M_iword;
698    }
699
700    /**
701     *  @brief  Access to void pointer array.
702     *  @param  __ix  Index into the array.
703     *  @return  A reference to a void* associated with the index.
704     *
705     *  The pword function provides access to an array of pointers that can be
706     *  used for any purpose.  The array grows as required to hold the
707     *  supplied index.  All pointers in the array are initialized to 0.
708     *
709     *  The implementation reserves several indices.  You should use xalloc to
710     *  obtain an index that is safe to use.  Also note that since the array
711     *  can grow dynamically, it is not safe to hold onto the reference.
712    */
713    inline void*&
714    pword(int __ix)
715    {
716      _Words& __word = (__ix < _M_word_size)
717			? _M_word[__ix] : _M_grow_words(__ix, false);
718      return __word._M_pword;
719    }
720
721    // Destructor
722    /**
723     *  Invokes each callback with erase_event.  Destroys local storage.
724     *
725     *  Note that the ios_base object for the standard streams never gets
726     *  destroyed.  As a result, any callbacks registered with the standard
727     *  streams will not get invoked with erase_event (unless copyfmt is
728     *  used).
729    */
730    virtual ~ios_base();
731
732  protected:
733    ios_base();
734
735  // _GLIBCXX_RESOLVE_LIB_DEFECTS
736  // 50.  Copy constructor and assignment operator of ios_base
737  private:
738    ios_base(const ios_base&);
739
740    ios_base&
741    operator=(const ios_base&);
742  };
743
744  // [27.4.5.1] fmtflags manipulators
745  /// Calls base.setf(ios_base::boolalpha).
746  inline ios_base&
747  boolalpha(ios_base& __base)
748  {
749    __base.setf(ios_base::boolalpha);
750    return __base;
751  }
752
753  /// Calls base.unsetf(ios_base::boolalpha).
754  inline ios_base&
755  noboolalpha(ios_base& __base)
756  {
757    __base.unsetf(ios_base::boolalpha);
758    return __base;
759  }
760
761  /// Calls base.setf(ios_base::showbase).
762  inline ios_base&
763  showbase(ios_base& __base)
764  {
765    __base.setf(ios_base::showbase);
766    return __base;
767  }
768
769  /// Calls base.unsetf(ios_base::showbase).
770  inline ios_base&
771  noshowbase(ios_base& __base)
772  {
773    __base.unsetf(ios_base::showbase);
774    return __base;
775  }
776
777  /// Calls base.setf(ios_base::showpoint).
778  inline ios_base&
779  showpoint(ios_base& __base)
780  {
781    __base.setf(ios_base::showpoint);
782    return __base;
783  }
784
785  /// Calls base.unsetf(ios_base::showpoint).
786  inline ios_base&
787  noshowpoint(ios_base& __base)
788  {
789    __base.unsetf(ios_base::showpoint);
790    return __base;
791  }
792
793  /// Calls base.setf(ios_base::showpos).
794  inline ios_base&
795  showpos(ios_base& __base)
796  {
797    __base.setf(ios_base::showpos);
798    return __base;
799  }
800
801  /// Calls base.unsetf(ios_base::showpos).
802  inline ios_base&
803  noshowpos(ios_base& __base)
804  {
805    __base.unsetf(ios_base::showpos);
806    return __base;
807  }
808
809  /// Calls base.setf(ios_base::skipws).
810  inline ios_base&
811  skipws(ios_base& __base)
812  {
813    __base.setf(ios_base::skipws);
814    return __base;
815  }
816
817  /// Calls base.unsetf(ios_base::skipws).
818  inline ios_base&
819  noskipws(ios_base& __base)
820  {
821    __base.unsetf(ios_base::skipws);
822    return __base;
823  }
824
825  /// Calls base.setf(ios_base::uppercase).
826  inline ios_base&
827  uppercase(ios_base& __base)
828  {
829    __base.setf(ios_base::uppercase);
830    return __base;
831  }
832
833  /// Calls base.unsetf(ios_base::uppercase).
834  inline ios_base&
835  nouppercase(ios_base& __base)
836  {
837    __base.unsetf(ios_base::uppercase);
838    return __base;
839  }
840
841  /// Calls base.setf(ios_base::unitbuf).
842  inline ios_base&
843  unitbuf(ios_base& __base)
844  {
845     __base.setf(ios_base::unitbuf);
846     return __base;
847  }
848
849  /// Calls base.unsetf(ios_base::unitbuf).
850  inline ios_base&
851  nounitbuf(ios_base& __base)
852  {
853     __base.unsetf(ios_base::unitbuf);
854     return __base;
855  }
856
857  // [27.4.5.2] adjustfield anipulators
858  /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
859  inline ios_base&
860  internal(ios_base& __base)
861  {
862     __base.setf(ios_base::internal, ios_base::adjustfield);
863     return __base;
864  }
865
866  /// Calls base.setf(ios_base::left, ios_base::adjustfield).
867  inline ios_base&
868  left(ios_base& __base)
869  {
870    __base.setf(ios_base::left, ios_base::adjustfield);
871    return __base;
872  }
873
874  /// Calls base.setf(ios_base::right, ios_base::adjustfield).
875  inline ios_base&
876  right(ios_base& __base)
877  {
878    __base.setf(ios_base::right, ios_base::adjustfield);
879    return __base;
880  }
881
882  // [27.4.5.3] basefield anipulators
883  /// Calls base.setf(ios_base::dec, ios_base::basefield).
884  inline ios_base&
885  dec(ios_base& __base)
886  {
887    __base.setf(ios_base::dec, ios_base::basefield);
888    return __base;
889  }
890
891  /// Calls base.setf(ios_base::hex, ios_base::basefield).
892  inline ios_base&
893  hex(ios_base& __base)
894  {
895    __base.setf(ios_base::hex, ios_base::basefield);
896    return __base;
897  }
898
899  /// Calls base.setf(ios_base::oct, ios_base::basefield).
900  inline ios_base&
901  oct(ios_base& __base)
902  {
903    __base.setf(ios_base::oct, ios_base::basefield);
904    return __base;
905  }
906
907  // [27.4.5.4] floatfield anipulators
908  /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
909  inline ios_base&
910  fixed(ios_base& __base)
911  {
912    __base.setf(ios_base::fixed, ios_base::floatfield);
913    return __base;
914  }
915
916  /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
917  inline ios_base&
918  scientific(ios_base& __base)
919  {
920    __base.setf(ios_base::scientific, ios_base::floatfield);
921    return __base;
922  }
923} // namespace std
924
925#endif /* _IOS_BASE_H */
926
927